Fix #513

[lynn9388]

Instead Go has a special type, the channel, which is a like a conduit (pipe) through which you can send typed values and which takes care of communication between goroutines, avoiding all the pitfalls of shared memory; the very act of communication through a channel guarantees synchronization. Data are passed around on channels: only one goroutine has access to a data item at any given time: so data races cannot occur, by design. The ownership of the data (that is the ability to read and write it) is passed around.

http://files.cnblogs.com/files/rojas/thewaytogo.pdf

而 Go 有一种特殊的类型，通道（channel），就像一个可以用于发送类型化数据的管道，由其负责协程之间的通信，从而避开所有由共享内存导致的陷阱；这种通过通道进行通信的方式保证了同步性。数据在通道中进行传递：在任何给定时间，一个数据被设计为只有一个协程可以对其访问，所以不会发生数据竞争。 数据的所有权（可以读写数据的能力）也因此被传递。

[unknwon]

感谢修正！